EndToEndWebHttpSecurityMode is used in the WebHttpRelayBinding constructors to set the security mode. As such, it is usually used at the beginning of an application, before the binding is used to connect to the Windows Azure Service Bus. Functionally, EndToEndWebHttpSecurityMode is very similar to EndToEndSecurityMode, and serves a similar role. The main difference is that the WebHttpRelayBinding has slightly different possible security settings, and so requires different options.